Fifteen of the caches are at the coordinates given for them. You need to record the number inside the lid of each cache to find the coordinates to a 16th cache (GC6NN4W) that contains a special geocoin for the FTF, featuring something else that Island Bay is famous for.
The coordinates for the 16th cache are South ABo CD.EFG East HIJo KL.MNO, where A is the number inside the lid of River Roads #1 – Dee Street, B is the number inside the lid of River Roads #2 – Tamar Street and so on up to O, which is inside the lid of River Roads #15 – Severn Street.
Tamar Street
Tamar Street is named after the River Tamar in south-west England that forms most of the border between Devon (to the east) and Cornwall (to the west). The area is a World Heritage Site due to its historic mining activities.
The Tamar's source is less than 6 km (3.7 mi) from the north Cornish coast, but it flows southward and its course runs across the peninsula to the south coast. The total length of the river is 61 miles or 98 km. At its mouth, the Tamar flows into the Hamoaze before entering Plymouth Sound, a bay of the English Channel. Tributaries of the river include the rivers Inny, Ottery, Kensey and Lynher (or St Germans River) on the Cornish side, and the Deer and Tavy on the Devon side.
The cache
This is a straightforward park ‘n’ grab, but is in a residential area, so please respect the residents’ privacy and be discreet. It’s on public land, so there’s no need to enter any private property or leave the road. Bring your own pen or pencil.
You are looking for a small glass jar. Please replace it exactly as you found it and do please log a DNF if you can’t find it. There’s no shame in a DNF! This is particularly important, as this is a series of caches in which all need to be active for finders to locate the final cache.